1. The present invention is directed to a safety barrier system for buildings, and in particular to a vertically extensible safety barrier for use in the construction of multi-storey buildings.
2. The history of constructing tall buildings is notoriously replete with the associated deaths of workers who fall from such structures. In the case of the Empire State Building in New York City tradition has it that each floor of elevation accounted for the loss of a worker's life.
Present day loss of lives, while not as scandalously high, is nevertheless too great. A common technique for building a high rise building is to erect formwork at ceiling height above an existing floor, lay reinforcement, and then pour concrete into the formwork to form the next floor. The installation of such formwork and reinforcement necessitates working at a highly exposed, poorly protected working level. Protective methods and apparatus currently in use include: low barriers to guard against accidental dislodgement of tools and materials from off the perimeter of the ‘working’ floor, and to safeguard workers from going beyond the floor perimeter; with peripheral safety nets strung about the perimeter of a lower floor, beneath the current working level and extending out from that floor. Being mounted upon vertical tracks, the nets can be raised, floor by succeeding floor, as the building progresses upwardly, However, while the net may save a life, the support structure for the net itself constitutes a hazard for anyone falling onto it.
When an overlying floor has been poured, support poles may be jacked into place between floor and ‘ceiling’, from which poles safety fencing may be secured, to restrain both individuals, their tools, and materials from falling. This latter system leaves open a dangerous accident ‘window’, until the succeeding floor has been poured, and the poles can be installed, which ‘windows’ constitute the most dangerous times of the building process, when workers are installing formwork and reinforcement while being totally unprotected against falling off the structure.